Shader "TideShader/1_UV动画旋转Flow"
{
    Properties
    {
        _MainTex ("Texture", 2D) = "white" {}
        _UVDir("UV旋转方向",vector) = (1,1,1,1)
        _Speed("旋转速度",float) = 1
    }
    SubShader
    {
        Pass
        {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #include "UnityCG.cginc"

            struct appdata
            {
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
            };

            struct v2f
            {
                float2 uv : TEXCOORD0;
                float4 vertex : SV_POSITION;
            };

            sampler2D _MainTex;
            float2 _UVDir;
            float _Speed;

            v2f vert(appdata v)
            {
                v2f o;
                o.vertex = UnityObjectToClipPos(v.vertex);
                o.uv = frac(_Time.y * _Speed) * _UVDir + v.uv;
                return o;
            }

            fixed4 frag(v2f i) : SV_Target
            {
                // sample the texture
                fixed4 col = tex2D(_MainTex, i.uv);
                return col;
            }
            ENDCG
        }
    }
}